(1) Background: Invasive aspergillosis is a life-threatening fungal infection, particularly in patients with hematologic malignancies. Isavuconazole, a broad-spectrum triazole, has emerged as a key treatment option, but real-world data in high-risk populations from middle-income countries remain limited. (2) Methods: We conducted a multicenter, retrospective study to evaluate the clinical response rate and tolerability of isavuconazole in patients with hematologic malignancies and probable or proven invasive aspergillosis across four medical centers in Brazil. (3) Results: We enrolled 50 patients aged 18 to 82 years (64% male) with proven or probable invasive aspergillosis, diagnosed in the context of complex hematologic conditions. Among them, 60% had active or refractory malignancies, and 22% had a prior COVID-19 infection. Isavuconazole was used as a first-line therapy in 64% of cases. No patients discontinued treatment due to toxicity. The 6-week overall survival was 60%. Prior COVID-19 infection was associated with a lower survival rate (44% vs. 69% in patients without COVID-19, p = 0.04). (4) Conclusions: This study provides real-world evidence supporting the efficacy and tolerability of isavuconazole in a high-risk population. The findings reinforce its role as a key antifungal therapy, particularly in patients with complex underlying conditions.
Keywords: COVID-19; antifungal; hematologic malignancies; hematopoietic stem cell transplantation; invasive aspergillosis; isavuconazole; opportunistic fungal infection.